Field of the Invention
The invention relate to a test plug block for slipping onto a modular terminal block, with a plurality of interconnected test plugs and two fastening parts which are located on either side of the plurality of test plugs and which are connected to one another via a handle, the fastening parts each having a housing with a plug-in section which can be plugged into a receiving section which is made in the clip housing of a mounting clip of the modular terminal block.
Description of Related Art
Electrical modular terminals have been known for decades and are used in the millions in the wiring of electrical installations and devices. The terminals are generally latched onto mounting rails which for their part are often located in a plurality in a switchgear cabinet. In switching, measurement and control engineering, feed-through terminals with a disconnect possibility are the standard. The disconnect possibility which is implemented in these feed-through terminals by the formation of a disconnect in the current bar makes it possible to plug different plugs with different functions into the terminal housing of the modular terminal which then make contact with the current bar at the disconnect. Plugs can be in addition to simple disconnect plugs and feed-through connectors in particular also test plugs which can have special components and which enable checking of proper operation of the circuit which is connected to the modular terminal.
Electrical modular terminals which are generally made disk-shaped are often mated to several other electrical modular terminals to form a modular terminal block and are latched onto a mounting rail or are mounted in a wall cutout, for example of a switchgear cabinet. Accordingly the individual test plugs which correspond in their width in general to the width of the modular terminals are connected into a test plug block and are jointly placed on a corresponding modular terminal block. In this case it is required that the number of interconnected modular terminals and the number of test plugs which are combined with one another to form a test plug block can be freely selected. But at the same time, the test plugs which have been combined to form a test plug block should be jointly actuated as simply as possible i.e., they can be slipped jointly onto the modular terminal block.
German Patent Application DE 10 2006 052 894 A1 and corresponding U.S. Pat. No. 7,666,037 B2 disclose a modular terminal, a test plug and a test plug block which is composed of a plurality of modular terminals which are located next to one another and a corresponding number of test plugs. By using two mounting clips and two fastening parts which each are located on either side of the modular terminal block or the test plug block, the number of modular terminals and the number of test plugs which can be combined to form a modular terminal block and a test plug block respectively can be freely selected. The two fastening parts are connected to one another via a handle so that the test plug block together with the two fastening parts can be easily and comfortably plugged into or slipped onto the modular terminal block and the two mounting clips using the handle. The handle is located on the top end of the fastening parts which have a greater height than the test plugs so that the handle bridges the test plugs which are located between the two fastening parts and in this way it can be easily grasped with one hand.
In order to ensure defined contact states when the test plug is plugged into the test opening, in the electric modular terminal known from German Patent Application DE 10 2006 052 894 A1 and corresponding U.S. Pat. No. 7,666,037 B2, the current bars are made such that they form two contact regions which are located behind one another in the slip-on direction of a test plug. Thus, in the known modular terminals, the disconnect formed by the end regions of the busbars is made two-stage. Making a defined second contact region which is located in front of the first contact region in the insertion direction of the contact plug ensures that when the contact plug is inserted, first a reliable electrical connection between the contact plug and the two current bars is formed before the first contact region is opened as the contact plug continues to be inserted, as a result of which the two current bars are then electrically disconnected from one another.
The above described known modular terminals and test terminal block share the feature that the two current bars make contact with one another so that the conductor connection elements are connected to one another in an electrically conductive manner when a plug has not been inserted into the modular terminal. If conversely a plug is (fully) plugged into the modular terminal, the contact region is interrupted so that the conductor connection elements are also electrically disconnected from one another.
Often the individual test plugs of the test plug block have contact plugs of different length. When the test plug block is slipped on, first the longer contact plugs of individual test plugs dip into the corresponding openings in the terminal housing of the modular terminals and make contact there with the leading contact region of the two current bars which is first in the slip-on direction of the test plugs. When the test plug block is slipped further onto the modular terminal block, the longer contact plugs dip into the second contact region, as a result of which this contact region is opened so that the electrically conductive connection between the two current bars and thus also between the two conductor connection elements which are connected to the current bars is interrupted. If the contact plugs are electrically conductive, in this way the current being carried via the test plug is diverted. If the test plug block is slipped further onto the modular terminal block, next the shorter contact plugs make contact first of all according to the leading contact region in the modular terminals before the shorter contact plugs also open the second contact region and in this way the current being carried by these modular terminals is interrupted and optionally diverted via the test plugs.
When the test plug is being pulled out of the modular terminal block, in many applications it is necessary or at least desirable for the longer contact plugs to still interrupt the contact region of the assigned modular terminals, while the shorter contact plugs are already pulled out of the second contact region of the assigned modular terminals so that the two current bars of the corresponding modular terminal again make contact, as a result of which the current is carried via the modular terminal. But here, in the known test plug blocks, there is the risk that by pulling the test plug block out of the modular terminal block too quickly or unevenly, the above described sequence, according to which the contact regions of some modular terminals are still opened by the longer contact plugs while a current transfer is taking place via other modular terminals to which the test plugs with shorter contact plugs are assigned, is not reliably or perfectly ensured. In this way an unstable or undefined electronic state of individual modular terminals of the modular terminal block can arise.